My glidecam also would move when I turned the handle, I had definite gimbal alignment problems. I have worked as a machinist, so I was able to repair mine. it sounds like your is having similar problems

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"What I need is an exact list of specific unknown problems we might encounter."

Have you checked to see if the gimbal bearings need any oil. Because they are shielded and not sealed they might loose some of their smoothness and some oil could help. We had to add oil to the bearings on a rig we bought before we started making our own. We now suggest our customers check the gimbal every once in a while just to make sure everything is working correctly.

If you rig pendulums very much, it is bottom heavy. The strange thing is that you say your drop time is three seconds which should show very little pendulum effect. That is why I wonder about the bearings. If you tighten the handle bolt assembly too much, you can induce friction which would make a bottom heavy rig have a longer drop time.

Move the rig back and forth in front of you and see how much it pendulums.

I haven't checked the bearings for oil. It's brand new, so I figured it would have enough. I'm guessing sewing machine oil would probably be about the best viscosity, right (IE, very light)? Before I oil the bearings, though, I'll wait to see what Glidecam has to say about the issue.

I've not made any modifications to the Glidecam in any way, except to glue on the spirit levels this weekend. I haven't tightened the handle bolt assembly, for example.

If I move the rig rapidly forwards and backwards, it pendulums a bit, but nowhere near as much as side to side.

Our sled is similar in configuration to Glidcam's but with some important differences so we're familiar with it's basic operation.

Do this for me...Hold the sled by the post so that the handle hangs freely. Now move the sled back and forth and see it the handle moves very easily. Since it's a new sled I'm guessing it's fine but that doesn't explain your problems. FYI, we oil with a 3-in-1 viscosity type oil.

Try this out also...Static balance the sled forward with a 2-3 second drop-time and then pan the camera 180 degrees. Does the post stay vertical or does it swing out?

Are your weights on the bottom plate the same distance and equal in number (weight) from the post?

Yes, the handle swings freely, I notice no sticking of any kind. There is some play in the handle, as I described earlier. Also, as previously described in an earlier message, the sled does not remain balanced when the handle is rotated 180-degrees (or camera panned).

As described in the first message in this thread, I have a total of 8 weights on the bottom plate, two sets of 4. They both started out at the extreme ends of the plate, but, to get the rig to balance again (after the camera came back heavier from the repair facility!), they've since been moved in towards the central post by about 1/4". I ended up fine-tuning the balance by moving the weights because the manufacturing tolorences I talked about above, meant I was "chasing" the balance and unable to get perfect static balance. However, in reading Charles Papert's posts about dynamic balance, he says to move the camera in the direction where's it's heaviest, and move the weights on the base plate in the opposite direction (IE. If it's front heavy, move it forward a little, then move the weights under the lens backwards to compensate). So, even though the weights are symmetrical in my case, they don't necessarily have to be!

I got en email from Tom at Glidecam. He agrees that there may be a problem with my gimbal being out of spec, and has asked me to ship the 4000 Pro back to him. I'm going to use the current setup for a test shoot this weekend, so I'll send it to him on Monday. He said he'll test my unit and either trim it, or replace it as necessary. I don't care either way, I just want to be able to use it to its full potential. Anyway, Glidecam was very responsive (they got the email this morning, and replied immediately with a solution) so I'm happy so far. I'll update this thread with my findings when I get the unit back in a couple of weeks.

I bought it brand new, through one of the dealers listed on the Glidecam web site. my guess is they'll replace it with a new one, which hopefully they will fully test for linearity prior to sending it to me.